Carb sync issues. any ideas

[SECTION8]

Ok so i got the carb sync all set up and turned her on and this is what I'm reading. #1,2,3 are all in the area showing intake manifold leak or late valve timing. The #4 is the only one that is reading different and it is showing late IGN timing. Advice?

[seestheday]

Sorry, maybe I'm not understanding the question... are you trying to sync them and it's not working?

Sync screws are on the carbs, and ideally you use a special screwdriver that has a wrench attachment so you can turn the screw and the locking bolt independently.  #2 carb isn't adjustable, you sync the other carbs to it.

EDIT: have you done a compression test?  I just re-read your post and think I get the question now.  My sync gauges don't have indicators for late ign etc on them.

[SECTION8]

I am trying to ask what is causing the one to be so far off. None of the screws to adjust are moving the needle on the gauge. Thats why I have the picture there. Maybe this requires someone to actually see the issue. never mind

[SECTION8]

Is where the needles are in the pic anywhere near where they are suppose to be...

[Piute]

   Hey Section 8 there's some vids in here may help

http://honda-cb750-s.456789.n3.nabble.com/Carb-Sync-tool-59-00-Cycle-X-TECH-TIPS-also-being-added-td3963996.html

                                             HOW ABOUT a few VIDEO's
                                                             

                                http://www.youtube.com/watch?v=IpqCUE8aCCk

                                     There's plenty here,(I havn't watch all YET)

[TOOLS1]

I have not done the carbs on a DOHC yet, but on the SOHC they seem to run best at 9# vacuum. Don't pay any attention to the diagnosis of the engine on the gauges. What screws are, you adjusting? Several guys have tried turning the fuel screws, and that just does not work. You adjust the ones on the linkage between the carbs.
TOOLS

[shinyribs]

Tools is right,just shoot for even,dont worry about the ''symptoms'' on the gauges. Remember that your #2 carb is non-adjustable.Whatever #2 is,make the others match and you'll be good to go.

Also,did your sync kit come with little valves? If it did use them inline on the hoses going to the gauge kit and all of your needle bouncing will go away. The valves help to lessen the ''blows'' from the vacuum pulses and will smooth the needle action out til it is rock solid. They should be little black pieces with thumb screws on them.

[cdaiscool]

What everyone else is saying too. The 'diagnosis' sections are not relative to motorcycles. I think the company that makes those got a helluva deal on those gauges, and goes with those. Just look at the vacuum reading, and go from there.

[LukeM]

Good advice. The little white restrictor valves do help stabilize the valves.  However, I would recommend you connect all 4 gauges to a single vacuum source, to make sure you have the same reading on all the gauges, and that the white valves (if you're using them) are set the same.

Rather than focusing on the inches of vacuum on each gauge, it's more important to make sure they all read as close to the same as you can get them.  It will be a compromise based on idle/part throttle/power band.

If you are within 5-10 degrees across the board at idle, and at about 2000-2500 rpm, I think you're in good shape.  Once you get them close to sync, you may have to adjust your idle down, as the balance will help the engine run better.  That's how I noticed my bike was getting better when I got them sync'd.

Luke M

[Lucky 1]

See how the needles are bouncing.

You need to turn the adjusters and get the gauges dampened down and not wiggling.

If you cannot stop the needle on the gauge from wiggling
it can mean the valve guides are worn out.

Vacuum gauges should read about 10Mg vacuum.

Also never turn the mixture screws to sync carbs.

[Lucky 1]

The instructions tell you that, that is a possibility and to send the gauge back.

[Lucky 1]

A very fast way to figure this out.

Take #4 gauge hose and hook it to #1.
If the gauge, is the SAME then the gauge has
a defect.

IF you take #4 gauge and hook it to #1 and it is DIFFERENT
then you know it is that engine cylinder, NOT the gauge.

[shinyribs]

FSM calls for 18-22 cm/hg on a SOHC. Do the DOHC's run that low of a vacuum signal?

[Lucky 1]

Depends on the rpm.

[Zx6rguy]

This post helped me so much, i used those small inserts inbetween the lines but didnt know they were used to slow down the needles. But i still have a problem, the needles are all about equal when i was syncing them but still in the red, i checked my valves and they were all fine......not sure what the problem is.

[TOOLS1]

Just ignore those other markings on the gauges. The only reading you need to worry about are the inches vacuum. You should be around 7 inches.
TOOLS